J/A+A/599/A76 L-σ relation for HII galaxies (Melnick+, 2017)
The L-σ relation for HII galaxies in green.
Melnick J., Telles E., Bordalo V., Chavez R., Fernandez-arenas D.,
Terlevich E., Terlevich R., Bresolin F., Plionis M., Basilakos S.
<Astron. Astrophys., 599, A76-76 (2017)>
=2017A&A...599A..76M 2017A&A...599A..76M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra; H II regions; Equivalent widths ;
Velocity dispersion
Keywords: distance scale - dark energy - galaxies: starburst -
galaxies: kinematics and dynamics
Abstract:
The correlation between emission-line luminosity (L) and profile-width
(σ) for HII galaxies provides a powerful method to measure the
distances to galaxies over a wide range of redshifts. In this paper,
we use SDSS spectrophotometry to explore the systematics of the
correlation using the [OIII]5007 lines instead of Hα or Hβ
to measure luminosities and line widths. We also examine possible
systematic effects involved in measuring the profile-widths and the
luminosities through different apertures. We find that the green
L-σ relation, defined using [OIII]5007 luminosities, is
significantly more sensitive than Hβ to the effects of age and
the physical conditions of the nebulae, which more than offsets the
advantage of the higher strength of the [OIII]5007 lines. We then
explore the possibility of mixing [OIII]5007 profile-widths with SDSS
Hβ luminosities using the Hubble constant H0 to quantify the
possible systematic effects. We find the mixed
L(Hβ)-σ[OIII] relation to be at least as powerful as the
canonical L-σ relation as a distance estimator, and we show that
evolutionary corrections do not change the slope and the scatter of
the correlation and, therefore, do not bias the L-σ distance
indicator at high redshifts. Locally, however, the luminosities of the
giant HII regions that provide the zero-point calibrators are
sensitive to evolutionary corrections and may bias the Hubble constant
if their mean ages, as measured by the equivalent widths of Hβ,
are significantly different from the mean age of the HII galaxies.
Using a small sample of 16 ad-hoc zero point calibrators we obtain a
value of H0=66.4+5.0-4.5km/s/Mpc for the Hubble constant, which
is fully consistent with the best modern determinations, and which is
not biased by evolutionary corrections.
Description:
We have combined data sets from our previous works, to which we have
added new measurements.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 50 102 Objects from Chavez et al. (2014,
Cat. J/MNRAS/442/3565)
table2.dat 50 30 Objects from Bordalo & Telles
(2011ApJ...735...52B 2011ApJ...735...52B)
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See also:
J/MNRAS/442/3565 : L-σ relation for massive star formation (Chavez+ 2014)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Name (1)
14- 19 F6.4 --- z Redshift
21- 24 F4.1 km/s sigma Velocity dispersion from [OIII]5007 line
26- 29 F4.2 km/s e_sigma rms uncertainty on sigma
31- 35 F5.2 [10-7W] logLHb Hβ luminosity
37- 40 F4.2 [10-7W] e_logLHb rms uncertainty on logHb
42- 46 F5.1 0.1nm EWHb Hβ equivalent width
48- 50 F3.1 0.1nm e_EWHb rms uncertainty on EWHb (2)
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Note (1): In table1, SDSS shorted names, JHHMMSS.
Note (2): In table2, assumed errors of 1.5Å.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 24-May-2017